1. Field of the Invention
The present invention relates to gas insulated substations for switching electric circuits in a power transmission system or a sub-station system.
2. Description of the Prior Art
FIG. 3 shows a configuration of conventional gas insulated substation which is described in a paper published by BBC in April, 1987, of which publication No. is CH-HS 111487. FIG. 4 is a single line diagram of the system including the gas insulated substation shown in FIG. 3. In the figure, reference numeral 1 shows a circuit breaker and 2 denotes disconnecting switches, 3 a ground switch, 4 a bus bar connected to other circuits in a gas insulated substation, 5 a transformer arranged out of the gas insulated substation, 6 an outgoing portion of the transformer, 7 an outgoing bus bar. The outgoing bus bar 7 includes horizontal portion 7a and vertical portion 7b for connecting the gas insulated substation to the outgoing portion 6 of the transformer 5.
In the gas insulated substation as described above, current flowing into the gas insulated substations through the bus bar 4 flows into the transformer 5 through the disconnecting switch 2, the circuit breaker 1, the other disconnecting switch 2, and the outgoing portion 6 of the transformer 5.
When grounding is required for inspection, etc., the ground switch adjacent to the inspected portion is closed for grounding. The outgoing bus bar 7 is arranged along two sides at right angles to each other, for example, horizontal portion 7a and vertical portion 7b as shown in FIG. 3, since the outgoing bus bar is generally installed by a crane.
The conventional gas insulated substation described above has a drawback that the outgoing bus bar 7 connecting the gas insulated substations and the transformer becomes long, resulting in poor economy due to the increase in the amount of the outgoing bus bar.